<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <ul class="nav">
      <li>a</li>
      <li>b</li>
      <li>v</li>
      <li>c</li>
    </ul>

    <script>
      // 闭包应用-3秒钟之后，打印所有li元素的内容
      let lis = document.querySelector('.nav').querySelectorAll('li')
      for (let i = 0; i < lis.length; i++) {
        /* ;(function (i) {
          setTimeout(function () {
            console.log(lis[i].innerHTML)
          }, 3000)
        })(i) */

        setTimeout(function () {
          console.log(lis[i].innerHTML)
        }, 3000)
      }
    </script>
  </body>
</html>
